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<meta charset="utf-8">
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<script src="../../js/js-test-pre.js"></script>
<script src="../../js/webgl-test-utils.js"></script>
<title>WebGL WEBGL_depth_texture Conformance Tests</title>
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<body>
<script id="vshader" type="x-shader/x-vertex">
attribute vec4 a_position;
void main()
{
    gl_Position = a_position;
}
</script>

<script id="fshader" type="x-shader/x-fragment">
precision mediump float;
uniform sampler2D u_texture;
uniform vec2 u_resolution;
void main()
{
    vec2 texcoord = (gl_FragCoord.xy - vec2(0.5)) / (u_resolution - vec2(1.0));
    gl_FragColor = texture2D(u_texture, texcoord);
}
</script>
<div id="description"></div>
<div id="console"></div>
<canvas id="canvas" width="8" height="8" style="width: 8px; height: 8px;"></canvas>
<script>
"use strict";
description("This test verifies the functionality of the WEBGL_depth_texture extension, if it is available.");

debug("");

var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas, {antialias: false});
var program = wtu.setupTexturedQuad(gl);
var ext = null;
var vao = null;
var tex;
var name;
var supportedFormats;
var canvas2;

if (!gl) {
    testFailed("WebGL context does not exist");
} else {
    testPassed("WebGL context exists");

    // Run tests with extension disabled
    runTestDisabled();

    // Query the extension and store globally so shouldBe can access it
    ext = wtu.getExtensionWithKnownPrefixes(gl, "WEBGL_depth_texture");
    if (!ext) {
        testPassed("No WEBGL_depth_texture support -- this is legal");
        runSupportedTest(false);
    } else {
        testPassed("Successfully enabled WEBGL_depth_texture extension");

        runSupportedTest(true);
        runTestExtension(true);
        runTestExtension(false);
    }
}

function runSupportedTest(extensionEnabled) {
    var name = wtu.getSupportedExtensionWithKnownPrefixes(gl, "WEBGL_depth_texture");
    if (name !== undefined) {
        if (extensionEnabled) {
            testPassed("WEBGL_depth_texture listed as supported and getExtension succeeded");
        } else {
            testFailed("WEBGL_depth_texture listed as supported but getExtension failed");
        }
    } else {
        if (extensionEnabled) {
            testFailed("WEBGL_depth_texture not listed as supported but getExtension succeeded");
        } else {
            testPassed("WEBGL_depth_texture not listed as supported and getExtension failed -- this is legal");
        }
    }
}


function runTestDisabled() {
    debug("Testing binding enum with extension disabled");

    var tex = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, tex);
    wtu.shouldGenerateGLError(gl, [gl.INVALID_ENUM, gl.INVALID_VALUE],
                              'gl.texImage2D(gl.TEXTURE_2D, 0, gl.DEPTH_COMPONENT, 1, 1, 0, gl.DEPTH_COMPONENT, gl.UNSIGNED_SHORT, null)');
    wtu.shouldGenerateGLError(gl, [gl.INVALID_ENUM, gl.INVALID_VALUE],
                              'gl.texImage2D(gl.TEXTURE_2D, 0, gl.DEPTH_COMPONENT, 1, 1, 0, gl.DEPTH_COMPONENT, gl.UNSIGNED_INT, null)');
}


function dumpIt(gl, res, msg) {
  return;  // comment out to debug
  debug(msg);
  var actualPixels = new Uint8Array(res * res * 4);
  gl.readPixels(0, 0, res, res, gl.RGBA, gl.UNSIGNED_BYTE, actualPixels);

  for (var yy = 0; yy < res; ++yy) {
    var strs = [];
    for (var xx = 0; xx < res; ++xx) {
      var actual = (yy * res + xx) * 4;
      strs.push("(" + actualPixels[actual] + "," + actualPixels[actual+1] + "," + actualPixels[actual + 2] + "," + actualPixels[actual + 3] + ")");
    }
    debug(strs.join(" "));
  }
}
function runTestExtension(unpackFlipY) {
    debug("Testing WEBGL_depth_texture. UNPACK_FLIP_Y_WEBGL: " + unpackFlipY);

    const res = 2;
    const destRes = 4;

    // make canvas for testing.
    canvas2 = document.createElement("canvas");
    canvas2.width = res;
    canvas2.height = res;
    var ctx = canvas2.getContext("2d");
    ctx.fillStyle = "blue";
    ctx.fillRect(0, 0, canvas2.width, canvas2.height);

    var program = wtu.setupProgram(gl, ['vshader', 'fshader'], ['a_position']);
    gl.useProgram(program);
    gl.uniform2f(gl.getUniformLocation(program, "u_resolution"), destRes, destRes);

    var buffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
    gl.bufferData(
        gl.ARRAY_BUFFER,
        new Float32Array(
            [   1,  1,  1,
               -1,  1,  0,
               -1, -1, -1,
                1,  1,  1,
               -1, -1, -1,
                1, -1,  0,
            ]),
        gl.STATIC_DRAW);
    gl.enableVertexAttribArray(0);
    gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, unpackFlipY);

    var types = [
        {obj: 'gl',  attachment: 'DEPTH_ATTACHMENT',         format: 'DEPTH_COMPONENT', type: 'UNSIGNED_SHORT',          data: 'new Uint16Array(1)', depthBits: "16"},
        {obj: 'gl',  attachment: 'DEPTH_ATTACHMENT',         format: 'DEPTH_COMPONENT', type: 'UNSIGNED_INT',            data: 'new Uint32Array(1)', depthBits: "16"},
        {obj: 'ext', attachment: 'DEPTH_STENCIL_ATTACHMENT', format: 'DEPTH_STENCIL',   type: 'UNSIGNED_INT_24_8_WEBGL', data: 'new Uint32Array(1)', depthBits: "24", stencilBits: "8"}
    ];

    for (var ii = 0; ii < types.length; ++ii) {
        var typeInfo = types[ii];
        var type = typeInfo.type;
        var typeStr = typeInfo.obj + '.' + type;

        debug("");
        debug("testing: " + type);

        // check that cubemaps are not allowed.
        var cubeTex = gl.createTexture();
        gl.bindTexture(gl.TEXTURE_CUBE_MAP, cubeTex);
        var targets = [
          'TEXTURE_CUBE_MAP_POSITIVE_X',
          'TEXTURE_CUBE_MAP_NEGATIVE_X',
          'TEXTURE_CUBE_MAP_POSITIVE_Y',
          'TEXTURE_CUBE_MAP_NEGATIVE_Y',
          'TEXTURE_CUBE_MAP_POSITIVE_Z',
          'TEXTURE_CUBE_MAP_NEGATIVE_Z'
        ];
        for (var tt = 0; tt < targets.length; ++tt) {
            wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION, 'gl.texImage2D(gl.' + targets[ii] + ', 0, gl.' + typeInfo.format + ', 1, 1, 0, gl.' + typeInfo.format + ', ' + typeStr + ', null)');
        }

        // The WebGL_depth_texture extension supports both NEAREST and
        // LINEAR filtering for depth textures, even though LINEAR
        // doesn't have much meaning, and isn't supported in WebGL
        // 2.0. Still, test both.
        var filterModes = [
          'LINEAR',
          'NEAREST'
        ];

        for (var jj = 0; jj < filterModes.length; ++jj) {
            debug('');
            debug('testing ' + filterModes[jj] + ' filtering');
            var filterMode = gl[filterModes[jj]];

            // check 2d textures.
            tex = gl.createTexture();
            gl.bindTexture(gl.TEXTURE_2D, tex);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, filterMode);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, filterMode);

            // test level > 0
            wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION, 'gl.texImage2D(gl.TEXTURE_2D, 1, gl.' + typeInfo.format + ', 1, 1, 0, gl.' + typeInfo.format + ', ' + typeStr + ', null)');

            // test with data
            wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION, 'gl.texImage2D(gl.TEXTURE_2D, 0, gl.' + typeInfo.format + ', 1, 1, 0, gl.' + typeInfo.format + ', ' + typeStr + ', ' + typeInfo.data + ')');

            // test with canvas
            wtu.shouldGenerateGLError(gl, [gl.INVALID_VALUE, gl.INVALID_ENUM, gl.INVALID_OPERATION], 'gl.texImage2D(gl.TEXTURE_2D, 0, gl.' + typeInfo.format + ', gl.' + typeInfo.format + ', ' + typeStr  + ', canvas2)');

            // test copyTexImage2D
            wtu.shouldGenerateGLError(gl, [gl.INVALID_ENUM, gl.INVALID_OPERATION], 'gl.copyTexImage2D(gl.TEXTURE_2D, 0, gl.' + typeInfo.format + ', 0, 0, 1, 1, 0)');

            // test real thing
            wtu.shouldGenerateGLError(gl, gl.NO_ERROR, 'gl.texImage2D(gl.TEXTURE_2D, 0, gl.' + typeInfo.format + ', ' + res + ', ' + res + ', 0, gl.' + typeInfo.format + ', ' + typeStr + ', null)');

            // test texSubImage2D
            wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION, 'gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 1, 1, gl.' + typeInfo.format + ', ' + typeStr  + ', ' + typeInfo.data + ')');

            // test copyTexSubImage2D
            wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION, 'gl.copyTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 0, 0, 1, 1)');

            // test generateMipmap
            wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION, 'gl.generateMipmap(gl.TEXTURE_2D)');

            var fbo = gl.createFramebuffer();
            gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
            gl.framebufferTexture2D(gl.FRAMEBUFFER, gl[typeInfo.attachment], gl.TEXTURE_2D, tex, 0);

            // Ensure DEPTH_BITS returns >= 16 bits for UNSIGNED_SHORT and UNSIGNED_INT, >= 24 UNSIGNED_INT_24_8_WEBGL.
            // If there is stencil, ensure STENCIL_BITS reports >= 8 for UNSIGNED_INT_24_8_WEBGL.
            shouldBeGreaterThanOrEqual('gl.getParameter(gl.DEPTH_BITS)', typeInfo.depthBits);
            if (typeInfo.stencilBits === undefined) {
                shouldBe('gl.getParameter(gl.STENCIL_BITS)', '0');
            } else {
                shouldBeGreaterThanOrEqual('gl.getParameter(gl.STENCIL_BITS)', typeInfo.stencilBits);
            }

            // TODO: remove this check if the spec is updated to require these combinations to work.
            if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE)
            {
                // try adding a color buffer.
                var colorTex = gl.createTexture();
                gl.bindTexture(gl.TEXTURE_2D, colorTex);
                gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
                gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
                gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
                gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
                gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, res, res, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
                gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, colorTex, 0);
            }

            shouldBe('gl.checkFramebufferStatus(gl.FRAMEBUFFER)', 'gl.FRAMEBUFFER_COMPLETE');

            // use the default texture to render with while we return to the depth texture.
            gl.bindTexture(gl.TEXTURE_2D, null);

            /* Setup 2x2 depth texture:
             * 1 0.6 0.8
             * |
             * 0 0.2 0.4
             *    0---1
             */
            const d00 = 0.2;
            const d01 = 0.4;
            const d10 = 0.6;
            const d11 = 0.8;

            gl.enable(gl.SCISSOR_TEST);

            gl.scissor(0, 0, 1, 1);
            gl.clearDepth(d00);
            gl.clear(gl.DEPTH_BUFFER_BIT);

            gl.scissor(1, 0, 1, 1);
            gl.clearDepth(d10);
            gl.clear(gl.DEPTH_BUFFER_BIT);

            gl.scissor(0, 1, 1, 1);
            gl.clearDepth(d01);
            gl.clear(gl.DEPTH_BUFFER_BIT);

            gl.scissor(1, 1, 1, 1);
            gl.clearDepth(d11);
            gl.clear(gl.DEPTH_BUFFER_BIT);

            gl.disable(gl.SCISSOR_TEST);

            // render the depth texture.
            gl.bindFramebuffer(gl.FRAMEBUFFER, null);
            gl.canvas.width = destRes;
            gl.canvas.height = destRes;
            gl.viewport(0, 0, destRes, destRes);
            gl.bindTexture(gl.TEXTURE_2D, tex);

            gl.disable(gl.DITHER);
            gl.enable(gl.DEPTH_TEST);
            gl.clearColor(1, 0, 0, 1);
            gl.clearDepth(1.0);
            gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
            gl.drawArrays(gl.TRIANGLES, 0, 6);

            dumpIt(gl, res, "--depth--");

            var actualPixels = new Uint8Array(destRes * destRes * 4);
            gl.readPixels(0, 0, destRes, destRes, gl.RGBA, gl.UNSIGNED_BYTE, actualPixels);

            const eps = 0.002;

            let expectedMin;
            let expectedMax;
            if (filterMode == gl.NEAREST) {
                expectedMin = [
                    d00, d00, d10, d10,
                    d00, d00, d10, d10,
                    d01, d01, d11, d11,
                    d01, d01, d11, d11
                ];
                expectedMax = expectedMin.slice();
            } else {
                expectedMin = [
                    d00, d00, d00, d10,
                    d00, d00, d00, d10,
                    d00, d00, d00, d10,
                    d01, d01, d01, d11,
                ];
                expectedMax = [
                    d00, d10, d10, d10,
                    d01, d11, d11, d11,
                    d01, d11, d11, d11,
                    d01, d11, d11, d11,
                ];
            }

            for (var yy = 0; yy < destRes; ++yy) {
                for (var xx = 0; xx < destRes; ++xx) {
                    const t = xx + destRes*yy;
                    const was = actualPixels[4*t] / 255.0; // 4bpp
                    const eMin = expectedMin[t];
                    const eMax = expectedMax[t];
                    let func = testPassed;
                    const text = `At ${xx},${yy}, expected within [${eMin},${eMax}], was ${was.toFixed(3)}`
                    if (was <= eMin - eps || was >= eMax + eps) {
                        func = testFailed;
                    }
                    func(text);
                }
            }

            // check limitations
            gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
            gl.framebufferTexture2D(gl.FRAMEBUFFER, gl[typeInfo.attachment], gl.TEXTURE_2D, null, 0);
            var badAttachment = typeInfo.attachment == 'DEPTH_ATTACHMENT' ? 'DEPTH_STENCIL_ATTACHMENT' : 'DEPTH_ATTACHMENT';
            wtu.shouldGenerateGLError(gl, gl.NO_ERROR, 'gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.' + badAttachment + ', gl.TEXTURE_2D, tex, 0)');
            shouldNotBe('gl.checkFramebufferStatus(gl.FRAMEBUFFER)', 'gl.FRAMEBUFFER_COMPLETE');
            wtu.shouldGenerateGLError(gl, gl.INVALID_FRAMEBUFFER_OPERATION, 'gl.clear(gl.DEPTH_BUFFER_BIT)');
            gl.bindFramebuffer(gl.FRAMEBUFFER, null);
            shouldBe('gl.getError()', 'gl.NO_ERROR');
        }
    }
}

debug("");
var successfullyParsed = true;
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